Performing the necessary insulin injection at the right time and in the right size is essential for managing diabetes, i.e. compliance with the specified insulin regimen is important. In order to make it possible for medical personnel to determine the effectiveness of a prescribed dosage pattern, diabetes patients are encouraged to keep a log of the size and time of each injection. However, such logs are normally kept in handwritten notebooks, from the logged information may not be easily uploaded to a computer for data processing. Furthermore, as only events, which are noted by the patient, are logged, the note book system requires that the patient remembers to log each injection, if the logged information is to have any value in the treatment of the patient's disease. A missing or erroneous record in the log results in a misleading picture of the injection history and thus a misleading basis for the medical personnel's decision making with respect to future medication. Accordingly, it may be desirable not only to automate the logging of ejection information from medication delivery systems, but also to provide a foolproof system.
Devices which log the time and size of the last injected doses are known in the art. One such device is known from WO 97/30742, which discloses a syringe having an electric representation of parameters such as magnitude of the set dose and the latest injected dose, which syringe further has a stop watch, the status of which is electronically represented and is together with electronic represented parameters reproduced in a display showing the number of hours passed since the last operation.
It is an object of a preferred embodiment of the present invention to provide a medication delivery device which comprises as few and as inexpensive components as possible, while at the same time being able to log the use pattern of the device and ejected information.
Furthermore it is an object of a preferred embodiment of the present invention to provide a solution, wherein patient security is high, such that a wrong drug is not inserted into the injection device by accident and such that dose log information of one type of medication is not mistaken for another.